syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3606/1:b..l
	(detected by 0, t=10502 jiffies, g=6565, q=274)
task:kworker/0:4     state:R  running task     stack:    0 pid: 3606 ppid:     2 flags:0x00000008
Workqueue: events nsim_fib_event_work
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6373
 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6777
 arm64_preempt_schedule_irq+0x174/0x2c4 arch/arm64/kernel/entry-common.c:260
 el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:463
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470
 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522
 fib_find_matching_alias net/ipv4/fib_trie.c:1024 [inline]
 fib_alias_hw_flags_set+0x190/0x934 net/ipv4/fib_trie.c:1047
 nsim_fib_event drivers/net/netdevsim/fib.c:882 [inline]
 nsim_fib_event_work+0xa24/0x33c4 drivers/net/netdevsim/fib.c:1483
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 process_scheduled_works kernel/workqueue.c:2373 [inline]
 worker_thread+0xb88/0x1034 kernel/workqueue.c:2459
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: rcu_preempt kthread starved for 10492 jiffies! g6565 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:    0 pid:   15 ppid:     2 flags:0x00000008
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6373
 schedule+0x11c/0x1c8 kernel/sched/core.c:6456
 schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x26c/0x13d4 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2145
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: Stack dump where RCU GP kthread last ran:
Task dump for CPU 1:
task:syz.2.18        state:R  running task     stack:    0 pid: 4232 ppid:  4170 flags:0x00000001
Call trace:
 __switch_to+0x308/0x588 arch/arm64/kernel/process.c:518
 0xfffff0000296e06b